free & open source software (foss): applications & technologies

Workshop on Census Cartography and Management, Lusaka, Zambia, 08–12 October 2007

Free &

Open Source Software (FOSS): Applications

&Technologies


FOSS: Applications & TechnologiesSummary

• Introduction

• Interoperability and Data Conversion

• The Geodatabase

• Desktop Mapping

• Geographical Analysis

• Web mapping

• GPS

• Conclusion


Free & Open Source (FOSS)• Applications of which you can access the source code • Similar functionality as commercial software

applications

• Becoming less IT oriented and more GUI friendly

• Provides useful information to users about the construction of applications

• Provide the ability to learn how to construct tailored applications for specific uses

• Allows for a more informed decision on what is needed outside the free and open source environment


Interoperability

• Defined by the The Global Spatial Data Infrastructure Association as… • “The capability to communicate, execute programs,

or transfer data among various functional units in a manner that requires the user to have little or no knowledge of the unique characteristics of those units.”

• [ISO 19118]


Interoperability & Data Conversion

• GDAL - Geospatial Data Abstraction Library (www.gdal.org)a translator library for raster geospatial data formats that is released under an Open Source license by the Open Source Geospatial Foundation. It comes with a variety of useful commandline utilities for data translation and processing of both raster and vector data

• Cartographic Projections library (remotesensing.org/proj)Reprojection of rasters and vectors among different coordinate systems and datum are managed by the PROJ library The precision is the same as for major commercial software, and may be increased with slight adaptations of the existing code. It includes several related resources as well

Workshop on Census Cartography and Management, Bangkok, Thailand, 15–19 October 2007

• Current Grids and Datums

(asprs.org/resources/GRIDS)• Since September 1998, the Grids and Datums column from

each issue of PE&RS has been made available on the web site

Interoperability & Data Conversion


GDAL - Geospatial Data Abstraction Library


Cartographic Projections Library


Grids and Datums (American Society for Photogrammetry & Remote Sensing)


Geodatabase

• PostGIS (postgis.refractions.net)

• Allows the storage and management of geographical vector data directly from within the database (thus using standard SQL and its Open Geospatial Consortium extensions: distance, area, buffer, overlay etc much like ESRI's SDE or Oracle's Spatial extension)

• Every record is associated to a specific projection, thus in the same database data in different projections can coexist, and they'll be correctly overlayed


• The data model is non-topological, and fully compliant to Simple Feature specifications of OGC (SFS 1.1, SFS TF 1.1).

• Importing and exporting ESRI shapefile data is straightforward. Raster geodatabase are not available.

• Users in Australia, British Columbia, Colorado, Portugal, Virginia, Georgia, Switzerland, Florida, Chile, Switzerland, Brazil, Sweden, Italy, Norway, New Zealand, Germany, Sri Lanka…

• WFP and FAO

Geodatabase


PostGIS


Desktop Mapping• Historically had a significant gap compared to commercial

applications, because most GFOSS users were IT persons, more inclined toward problem solving than to graphical appearance

• In the last few years, thanks also to a larger user base, the situation has vastly improved

• QuantumGIS (http://qgis.org) • most advanced raster vector image and data display and

manipulation• Thuban (http://thuban.intevation.org)

• strong limitations in the handling of rasters• OpenEV (http://openev.sourceforge.net)

• powerful in image analysis -not easy for the unexperienced user


Quantum GISor

QGIS


QGIS Interface


Geographical Analysis• Short for Geographic Resources Analysis Support System• Historically known as a raster GIS, difficult to use, mainly

command-line oriented, since 2002 it has known a heavy development; the 2D and 3D vector section, as well as the database integration, have been completely rewritten, and it is now available as a new (6.0) stable version.

• Very complete, with all functions required for a professional use, from management and analysis of geospatial data to image analysis, from chart and maps production to spatial modelling and 2D, 2,5D, and full 3D visualization; a complete list of the >350 modules (many of which with several options, giving a total of more than 600 commands

• Can Be Accompanied with R statistical package (http://www.r-project.org) and a flow through with QGIS


GRASSInterface


Map Server Applications

• Definition: Web Map Server-A service that can produce maps drawn into a standard image format (PNG, GIF, JPEG, etc). (GSDI Association ) based on a standard set of input parameters

• The first Mapserver (also called UMN Mapserver: http://ms.gis.umn.edu) has been developed originally by the University of Minnesota. It is OGC compliant (WMS 1.1.0, WMS 1.0.0, WMC 1.0, WFS 1.0.0, SLD 1.0, GML 2.0, Filter 1.0.0, WMS 1.1.1)

• Examples include pmapper (http://pmapper.sourceforge.net), Chameleon (http://chameleon.maptools.org) and Cartoweb (http://www.cartoweb.org)

• With these tools, customized map server applications can be built in a very cost-effective way


http://ms.gis.umn.edu


p.mapper


http://webgrs.wur.nl/cgi/Miscellaneous/EthioAtlas

p.mapper & Mapserver


GPS (Free & Open Source)

• Global Positioning System receivers are very useful and widespread;

• Many free programs are available for interacting with GPS hardware, from single-purpose command-line downloading programs (e.g. gpstrans: http://gpstrans.sourceforge.net) to the more sphisticated ones, with graphical interface and conversion tools (e.g. gpsbabel: http://gpsbabel.sourceforge.net);

• Some have real-time navigation application (e.g. gpsdrive: http://www.gpsdrive.cc) or differential correction (dgpsip:http://www.wsrcc.com/wolfgang/gps/dgps-ip.html).


GPS data integration

• Easy integration among different tools, characteristic of open source programs, allows larger programs like GRASS and QGIS to – and upload points and tracks straight from/to the devices.

• In the case of GRASS, data are reprojected automatically in the working projection and converted to the GRASS

vector format.


gpstrans


GPSBabel


Differential GPS Correction


FOSS: Online Resources

•Open Source Geospatial Foundation: http://www.osgeo.org

•The FreeGIS Project: http://www.freegis.org

•Map Tools & Utilities: http://maptools.org

•Open Source GIS: http://opensourcegis.org

•Remote Sensing Open Source Support: http://remotesensing.org

•Open Source Geospatial Consortium: http://www.opengeospatial.org/


Open Source Geospatial Foundation: http://www.osgeo.org


The FreeGIS Project:http://www.freegis.org


Map Tools & Utilities:http://maptools.org


Open Source GIS: http://opensourcegis.org


Remote Sensing Open Source Support: http://remotesensing.org


Open Source Geospatial Consortium: http://www.opengeospatial.org/


• Several products are mature and ready for professional use, whereas others, while usable, need further development to be really competitive (setting aside the cost of acquisition):

• UMN Mapserver is fully functional; it does not have significant limitations, and in several respects it is superior to its commercial counterparts

• PostgreSQL+PosGIS as a relational geodatabase is a very reliable and powerful solution, and has already replaced commercial top-end solutions

Conclusion

Workshop on Census Cartography and Management, Bangkok, Thailand, 15–19 October 2007

Conclusion

• For geographic analyses, GRASS is fully functional, stable and very powerful. In many situations (where money is an issue: underfunded universities and public administrations, small or heavily competing companies, etc.) it is the best alternative to the (unfortunately very common) illegal use of (cracked or stolen) proprietary software. Its inherent qualities, however, allow its use also in large and more complex settings

• Desktop mapping (and in particular QGIS) is usable, but still young; some more months of development will be necessary to make it more stable and powerful


Open Source Contributions?

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